Predictable Interrupt Management for Real Time Kernels over conventional PC Hardware1

In this paper we analyze the traditional model of interrupt management and its incapacity to incorporate reliability and the temporal predictability demanded on real-time systems. As a result of this analysis, we propose a model that integrates interrupts and tasks handling. We make a schedulability analysis to evaluate and distinguish the circumstances under which this integrated model improves the traditional model. The design of a flexible and portable kernel interrupt subsystem for this integrated model is presented. In addition, we present the rationale for the implementation of our design over conventional PC interrupt hardware and the analysis of its overhead. Finally, experimental results are conducted to demonstrate the deterministic behavior of our integrated model and to quantify its overhead